The present invention relates to a novel module housing for semiconductor devices and, more specifically, relates to a novel module structure employing an IMS (insulated metal substrate), one or more printed circuit boards, interconnects and other components in a novel housing structure.
Known semiconductor device modules are used for housing a plurality of interconnected semiconductor chips. The chips may be of the same or of diverse kind and may be mounted on a heatsink or other substrate within a common housing having terminal electrodes which extend from the housing.
In a power application, such as for a motor control circuit or similar functions, both high power devices, from which heat must be removed, as well as low power devices, which do not require heatsinking, are employed. Typically, the heatsinking may be provided by mounting the devices on an IMS which is enclosed in a module housing. Such substrates and modules are described in U.S. Pat. No. 5,408,128, issued Apr. 18, 1995 in the name of the inventor of the present application and assigned to International Rectifier Corporation, the present assignee. However, when both power and low power devices are required for an application, the inclusion of low power devices on an IMS greatly increases the cost of the module. Alternatively, the high power devices are included within the IMS module and the low power devices are mounted externally in other modules, thus greatly increasing the footprint of the circuit as well as requiring additional interconnections between the high and low power devices.
It is therefore desirable to provide a device package which houses both the high and low power devices and in which the package size is reduced, the number and lengths of interconnects are minimized, and in which heatsinking is provided only for the high power devices.